Castro is starting in center field and hitting first in Sunday's series finale against the Royals.
With JaCoby Jones hitting the injured list with a fractured wrist, Castro and Victor Reyes figure to pick up the slack in center field, with Castro also able to play some infield. The 25-year-old has a respectable .282 batting average through 58 games this season and figures to get some more chances as the leadoff hitter the rest of the way.